Undecidable Equivalences for Basic Parallel Processes

Hans Hüttel

Abstract: Recent results show that strong bisimilarity is
decidable for the class of Basic Parallel Processes (BPP), which
corresponds to the subset of CCS definable using recursion, action
prefixing, nondeterminism and the full merge operator. In this
paper we examine all other equivalences in the linear/branching
time hierarchy and show that none of them are decidable
for BPP.